<style>
    .footer {
        position: absolute;
        bottom: 0;
        width: 100%;
        height: 100px;
        padding: 3px;
        text-align: center;
    }
</style>
<footer class="footer">
    <br><br>
    <ul class="list-unstyled text-small">
        <li>&copy; Copyright 2021 Animal Adoption</li>
    </ul>
</footer>